Method of magnetically separating ores.



C. Q. PAYNE. METHOD 0F MAGNETIGALLY SEPARATING DRES.

APPLIOATION FILED MIL15, 1911.

Patented June-13, 1911.

2 SHEETS-SHEET 1.

G. Q; PAYNE. l METHOD OF MAGNETIOALLY SEPARATING CRES.

APPLICATION FILED MAR. l5, 1911.

Patented June 13,1911.

2 SHEETS-SHEET 2.

WIT/VESSEL? CLARENCE a. rerun, or nnss' nona, n. a.

' METHOD OF MGNETICALLY SEFRATING RE.

sensei.

Specification of Letters Patent. ltdaftqgiftgqll Juin@ 13, Ilfl.

Application led March 115, 1911. Serial No.J 514,53?.`

To all whom it may concern.;

Beit known that I, CLARENCE Q. PAYNE, a citizen of the United States ofAmerica, and'residing in the borough of Manhattan, city, county, andState of New York; have invented certain new and useful ImprovementsA inMethods of Magnetically Separating Ores, of which the following is afull and true description.

My invent-ion relates to improvements in methods ot'separatingsubstances ot' all degrecs of magnetic susceptibility from one anotheror from non-magnetic substances with which they may be mixed.

It consists essentially 1n a method of overl coming mechanicalinterference or entanglement of the various particles ot' an ore mixturewith each other while in a magnetic field, and whereby uniformconditions are provided for the attachment of the attracted particles.

I have found that mechanical entanglement is due to two principalcauses, lirst, tol

the presence of particles diiering greatly in size in an orc mixture,whereby the large particles when acted upon by magnetic attraction,Wedge and hold the similar particles not so acted upon and prevent theirtree motion; and, secondly, to the unequal action. of' magneticattraction, especially upon the smaller particles when they are affordedareal rather than lineal positions of attachment upon the separatingsurface.

I have succeeded in overcoming mechanical entanglement in a method oimagneticallyv separating ores by dividing the'ore mixture to beseparated into groups by sizingit so that the particles in each groupwillbe as nearly uniform in size as possible, and-then treating eachgroup independently upon a separating surface so formed that theparticles acted upon by magnetic attraction are permitted lineal orindependentpositions instead of areal or massed positions of attachment,and will be tree to respend to the forces of gravity and magneticattraction to which they are subjected. i

In my accompanying application, Serial No. 614,585., filed March15,1911, vI have described and claimed a general method et separatingores which includes both a magnatio andan electrostatic method. I havealso claimed .in the said application the specii'ic method Jetseparation described there-- in as the electrostatic method. Vllheclaims of this application are limited to the modi- Patent No, 791,494,dated June 6th, 1905, .as Well as in several other` patents granted tome, tosc control the positions of the lines l of force in a magneticfield as to secure what may be'called a unipolar field, z'. e., one inwhich the lines of force all pass in the same direction and do notreverse at any point. This I accomplish by causing the separation totakeplace in an air-gap of amagnctic circuit, between two opposing polepieces. In this waya large amount of mechanical interference orentanglement of the particles undergoing separation is prevented, ascompared with the use of a bipolar Heldin which loops or bridges ofattracted particles are permitted to span the space between the adjacentpoles, and thus surround and inclose a considcrable'amount' ofnon-magnetic material. ligt-withstanding the use of the unipolar field,a considerab e amount of mechanical entanglement has heretofore stillpersisted. Ihis mechanical entanglement it is the purpose of myinvention to overcome, and at the same time to exert as uniform aneffect as possible upon the attracted cparticles while they areundergoing separation.

In the drawing accompanying and form ing a part oit this specification,Figures 1, 2, 3 and -i are detail views illustrating the principle ot myinvention, and show upon an enlarged scale sections 4of disks VWhosethickness bears a certain ratio or size relation to the diameter of theparticles which they are illustrate more clearly what is sought to beaccomplished hy my invention, I have shown in Fig. V1 in section upon amuch enlarged scale a series ot disks it. fi ot soft iron or steelhaving smooth edge Jaces. These disks are alternately interleaved with aseries of magnetized, while the particles D D do notv so respond and are`hence free to be removed byV other forces, it is evident that in thepositions in which the particles D D are placed,vthey are held orblocked by the irregular shape of the attracted particles C C,

and their separation from the latter is thusprevented'. Thisinterference or mechanical entanglement of a certain percentage of oneset of particles D D by another set C C, hasthe obvious disadvantagethat the entangled. particlesD D are caused to pursue the same path ofmovement as the particles-C C when they are nally/ released anddischarged from their separating cylinder at the end of the field,instead of a diverse path of movement, 'thiis causing a defective orineticient separation. It is evident that if the smaller particles D Dare removed from the larger ones C C by screening them out before theore mixture is fed upon the separating cylinder A B their mechanicalentanglement would be prevented. lt is also evident that since the morehighly charged edges of the disk faces largely determine the position ofthe attracted particles, the thickness of the disks should not bedisproportionatelygreat as compared with the diameter of the particlesto be separated. For illustration if in Fig. 1 only particles of thesize C C be treated upon the disks A B whose thickness bears to thediameter of the particles C C approximately the ratio 2 :1, there willthen be little or no 'mechanical entanglement between particles of suchvrelative size while they are undergoing separation, and an efficientseparation can then be made.

, The videal conditions for sized particles may be assumed to berealized when the thickness ofthe disks is just equal to the diameterofthe particles to 'be separated'. Each attracted particle then almostinstantly finds a point of attachment when fed upon the cylinder made upof such disks, and the free distribution of the attracted particles uponthe separating surface is thus aided.-

Such a size relation, however, is not feasible in practical work, and lhavefound that a ratio of the thickness of the disks to the diameter ofthe -particles of 3 :1, 4:1, or even somewhat greater, will givepractical and eii'icient results, especially when the re mixture isproperly fed. upon the separating cylinder. l

ln Fig. 2 is illustrated the eect of the disproportionate size relationbetween the thickness of a magnetized disk, and the diameter of -thesized particles Ato he separated. -Here the attracted particles C tendtoI form column-like attachments especially toward theedge of the diskswhere magnetic density is greatest, and considerable mechan-'icalientanglement ef the non-attracted particles D is thus caused amongthem.` yFhis can be largely prevented `by using thinner disks for thesmall particles, as shown in Fig. 3 by A2 A2 and B2 B2, and by properlyfeeding the ore4 mixture upon the separating cylinder.

-ln Fig. 4 is illustrated an appropriate size relation in the case ofstill smaller ore particles C3 C3. l have found that-the best resultsare obtained when thin disks are used for the separation of particles ofsmall size,l

medium thick disks for medium size particles, and thick disks forcoarser particles,

in other words an approximately similar size relation should existvbetween the thickness of the disks and the average diameter of theparticles of each group treated upon` them respectively. Theexactiiumber of the group divisions into which an ore mixture should besubdivided, also the` number of separating cylinders employed, andthepre-l l cise ratio of the thickness of the disks of each cylindertotheaverage diameter of the particles of each group division will varywith the different -ore mixtures, but it is evident that the sizing anddisk variations may be carried to as great a degree of refinement as thevalue of a given ore and the resultingA gainin eiiiciency will warrant.

In Fig. 5 l have shown a complete separating cylinder such as may beemployed in carrying out my present invention. Here the separatingsurface consists of two series of disks mounted upon a shaft E, and heldin place by means of compression flanges F F. One series A? A4 is madeof iron or soft steel, and the other -series B4 B4 of a nonmagneticmaterial, such as liber, etc. The disks have smooth edge faces and thoseof one series, are alternately interleaved with those vof the other asshown in Fig. 5. ln place of the interleaved noninagnetic disks Bt it isalso possible to employ mag' netizable disks A4 alone, and to constructthem with alternately projecting edges as shown in Figj or else to give.their edges toothed outlines as shown in Fig. 7. The latterconstruction, especially when the disks are so assembled that the teetharestaggered or are out of alinement permits, in such cases where it isfound desirable,asomewhat more intense localization of the magneticattracting force than in the case of the interleaved disks with smoothedges. rlhe latter, on the other hand, aord somewhat more uniformconditions under which the attracting force acts upon the magneticparticles of an ore mixture while being conveyed through the magneticAfield. y i

lt is obvious that the specific arrangements of disks shown in Figs. 5,6 and'7 may be modified by those skilled in the art in practicing myinvention without departing elo from' the scope of my claims. It isessential, however, that the disks be so arranged as to. securemagnetically exposed disk edges along the surface of the separatingcylinder, in order that the attracted particles may be afforded as faras possible lineal positions of attachment while undergoing separation.

In Fig. 8 `l have shown 1n sectional view a'magnetic separator adaptedfor use in carrying out Amy invention. `Here W represents the'coil of anelectromagnet which, when energized by an electric current, establishesa magnetic eld betwen the pole ieces M N. The edges of the magnetizabledisks which Wholly or partly make up the armature-cylinder A lthenbecome charged with local condensations of magnetic'lines of force whenit is revolved through the field formed between ,the *p ole pieces M N.Those particles oftheore mixture fed upon the cylinder A from 4'a"convenient hopper H and guide plates G,.`Which'.are susceptible tomagneticl attraction are held to the charged edges' ofthe disks whilethey are being conveyed through 'the magnetic field, and are dischargedfrom the cylinder at the end of the field ina different path of movementfrom those particles of the ore mixture which are not 4acted on bymagnetic attraction, thus aflecting a separation between them.

in carrying out my improved invention each ore mixture is first dividedinto sev eral groups, preferably by screening it, so thatthe averagediameter of the particles in `each `group differs respectively amongthen'iselves'.v rThese groups arethen treated upon l.several separatorsof the type which I have shown in Fig. 8 and which dider amongthemselves in the thickness of the .disksfwhich arcrespectively used inthe separating cylinders. The group containing the lco'arsest oreparticles is then separatedupon the cylinders containing the thickestdisks,

while the group containing the finest ore particles is treated upon thecylinder containing the thinnest disks. rlhe greater the number of thegroups into which an ore mix- Y `ture is divided, and the more closelythe thickness of the disks approximates to the size of the ore particlesin each group the more perfectly can the mechanical entanglement of oneset4 of particles with another set, during separation, be overcome, andthe more perfect will the separation then become, While practicalconsiderations based upon the value 'of a given ore and the expenseinvolved in its treatment will necesmodify the ideal conditions alreadyin connection with overcoming mechanical entanglement, it is evidentthat there must be at least two groups of particles into which an oremixture must be divided, and that at least two separating cylinders mustbe employed having disks of diierent thicknesses in order to apply mymethod of separating to ore mixtures in accomplishing the purpose of myinvention.

I am aware that the sizing of ore mixtures as a preliminary step totheir treatment by various methodsof separation is not uncommonlypracticed, but it will be seen that the main feature of my inventionconsists in providing unobstructed positions of attachment for thoseparticles in an ore mixture which are acted on by magnetic attraction,and as a further aid in thus overcoming mechanical entanglement, I havefound that a preliminary sizing of the ore particles is of assistance.

VIclaim as my invention:

1. The method of magnetic ore separation which consists in dividing anore mixture into a plurality of groups which differ respectively in theaverage diameter of their particles, and subjecting each of said groupsindependently to the inagnetized edges of disks arranged in series,which disks vary in` thickness with the average diameter of theparticles acted on. v 2'. The method of magnetic ore separationwhich'consists in dividing ore into a plurality of groups differingrespectively in the average diameter of'their particles, and subjectingeach of said groups independently to the separating action of a seriesof mag# netic charges spaced proportionately to the average diameter ofthe particles of the group treated, substantially as described.

3. The method of .separating substances of all degrees of magneticpermeability from one another, or from non-magnetic substanceswithfwhich they may be mixed, which consists in dividing such an ore mixtureinto a plurality of groups which differ respectively in the averagediameter of their particles; feeding each group separately upon one of aplurality of' cylinders each of which is provided with a series ofmagnetic and non-magnetic disks placed alter-V :mer

nately which (lider in their thickness, each series with respect to theothers, acting upon each group by means of magnetic attrac-4 tion aswell as gravity and centrifugal force, and discharging two or more setsof separated particles from each cylinder along diverging paths ofmovement.

CLARENCE Q. PAYNE. l/Vitnesses WALTER S. Jones,

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